The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In the course of integrated circuit evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs. During the scaling trend, some photolithography enhancement techniques such as optical proximity correction (OPC), phase-shift mask (PSM), and off-axis illumination have been developed to compensate for image errors or to improve image resolution.
Generally, a semiconductor device such as a metal oxide semiconductor (MOS) device is constructed by a gate, a source and a drain. In some applications, a dummy gate is disposed near the gate to homogenize the optical proximity effect caused by light diffraction. However, the dummy gate may be peeled and thus damage the gate. Therefore, there is a need to solve the above deficiencies/problems.